Rotating machine abnormality detection device and rotating machine abnormality detection method

Abstract

A rotating machine abnormality detection device of an embodiment includes a non-contact acoustic emission sensor, an analyzer, and a diagnoser. The non-contact acoustic emission sensor, arranged at a position spaced away by a predetermined distance from a measurement target acting as a rotating member or a measurement target rotatably supporting the rotating member, is configured to detect acoustic emission that occurs during rotation of the measurement target or the rotating member supported by the measurement target and propagates in an atmosphere. The analyzer is configured to perform time-frequency analysis on a detection signal of the non-contact acoustic emission sensor. The diagnoser is configured to detect occurrence of a rotation abnormality when a frequency component equal to or larger than a predetermined threshold value is present in a predetermined frequency band, based on an analysis result of the analyzer.

What is claimed is: 
     
       1. A rotating machine abnormality detection device comprising:
 a non-contact acoustic emission sensor arranged at a position spaced away by a predetermined distance from a measurement target acting as a rotating member or a measurement target rotatably supporting the rotating member, the non-contact acoustic emission sensor being configured to detect, within a predetermined time, acoustic emission that occurs during rotation of the measurement target or the rotating member supported by the measurement target and propagates in an atmosphere; 
 an analyzer configured to perform time-frequency analysis on a detection signal of the non-contact acoustic emission sensor; and 
 a diagnoser configured to detect occurrence of a rotation abnormality when a frequency component with amplitudes equal to or larger than a predetermined threshold value is present in a 50 kHz frequency band within the predetermined time, and a sum of the amplitudes of the frequency band within the predetermined time exceeds a predetermined value, based on an analysis result of the analyzer, the amplitudes equal to or larger than the predetermined threshold value not being a peak and a zero. 
 
     
     
       2. The rotating machine abnormality detection device according to  claim 1 , wherein
 the non-contact acoustic emission sensor is configured as a laser microphone using a principle of a Fabry-Perot interferometer. 
 
     
     
       3. A rotating machine abnormality detection method that is performed by a rotating machine abnormality detection device that includes a non-contact acoustic emission sensor, arranged at a position spaced away by a predetermined distance from a measurement target acting as a rotating member or a measurement target rotatably supporting the rotating member, configured to detect, within a predetermined time, acoustic emission that occurs during rotation of the measurement target or the rotating member supported by the measurement target and propagates in an atmosphere, the rotating machine abnormality detection method comprising:
 performing time-frequency analysis on a detection signal of the non-contact acoustic emission sensor; and 
 determining when a frequency component with amplitudes equal to or larger than a predetermined threshold value is present in a 50 kHz frequency band within the predetermined time, whether or not a sum of the amplitudes of the frequency band within the predetermined time exceeds a predetermined value based on a result of the time-frequency analysis, and when the sum of the amplitudes of the frequency band within the predetermined time exceeds the predetermined value, detecting occurrence of a rotation abnormality, the amplitudes equal to or larger than the predetermined threshold value not being a peak and a zero.